This invention relates to an all-metal pipe coupling that is short, flexible, and capable of expanding and contracting. In more detail the invention relates to such a pipe coupling for use in connecting pipes carrying a liquid metal wherein the pipes are submerged in the same liquid metal. The invention also relates to a fast reactor safety test reactor incorporating such a coupling.
A need exists for a pipe coupling that is short, flexible, capable of expanding and contracting and that will withstand the environment of a liquid-metal-cooled nuclear reactor. The last requirement precludes the use of plastic or rubber materials and essentially makes it necessary to form the connector solely of a metal such as stainless steel for metal-to-metal contact with the stainless steel pipes being connected.
A tank-type liquid-metal-cooled nuclear reactor includes a reactor, one or more pumps and one or more heat exchangers all submerged in sodium filling a large tank. A pipe connects the reactor vessel with a heat exchanger. If sufficient space is available, this pipe can contain a loop to allow for deflection and expansion or contraction of the components. Such allowance must be made for thermal effects as well as possible seismic shock. A problem arises if the design of the system does not provide sufficient room to incorporate a loop in this connecting pipe.